Can a sip of orange juice cause blockage in throat making breathing difficult ?

I had a drop of orange juice in my throat and my throat started to close. I cold hardly breathe, every breath sounded terrible, and I felt as if I had no air going in. A terrible feeling. About to cal 911 but it gradually opened up again.
This lasted about 45 seconds or so.

I can appreciate that you had a very worrisome experience just now. I am glad to hear you are feeling better however. Sometimes acidic beverages such as orange juice can trigger some inflammation in the back of the throat or upper part of the airway. If a small amount gets into the upper airway it can trigger some inflammation. This will usually resolve within 15-30 minutes but on rare occasion it can cause more worrisome symptoms with breathing difficulty.

I suspect you had a mild degree of inflammation going on which gave you the sensation that your throat was closing up. I would recommend you continue to monitor things for the time being, hydrate with some water and monitor your symptoms. If you continue to feel progressively better over the next few hours then there should be no need to go to the hospital. If, however, you have a return of the sensation which you described or you have some breathing difficulty then you should call for transportation to the hospital.

I hope my answer has been both informative and adequate for you. If you have additional questions, I am avialable to answer them.